JPH0224639B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lining construction method using clad pieces.

Chemical equipment, especially the walls of tanks, are often lined with highly corrosion-resistant metal materials. procedures are being tried.

However, in explosive bonding, the thickness of the clad metal plate is generally 2 mm or more, and the minimum thickness of the backing material is about 9 to 12 mm. Since the preferred thickness of the backing material is about 1 mm, it takes a lot of man-hours to perform rolling or other processing to the required thickness. In addition, for mutual welding of such explosive clad materials, the tantalum surface layer along the edges of the backing material is usually scraped off and welded to the backing material, and then a thin tantalum plate covering this weld is attached to the tantalum surface layer. However, since the melting point of tantalum (2996℃) is much higher than that of copper (1083℃), the copper plate melts and alloys when welding the plate, causing performance deterioration. Construction is accompanied by significant difficulties.

Therefore, the present invention has developed a lining construction method using clad pieces that does not have such drawbacks.

In this invention, highly corrosion-resistant metal materials such as titanium, tantalum, niobium, and zirconium are made of highly corrosion-resistant metal materials, such as titanium, tantalum, niobium, and zirconium, with a thickness selected so that the required performance can be achieved at the dimensions that suit the usage conditions, such as the pressure of the tank and sometimes the degree of vacuum. The sheet is welded by electric resistance welding, such as spot welding or seam welding, to one side of a backing material made of titanium, copper or alloys thereof, or iron or alloys thereof, and having a thickness sufficient to provide sufficient reinforcement of the sheet. Clad pieces combined by local joining are used.

Here, the surface layer of the thin plate is overlapped over the entire surface of one side of the backing material, and a free overhanging edge extending from the edge to at least the width of the butt weld bead to be applied to the backing material is left during the above-mentioned local joining. This makes it easier to perform welding together with the base material in the butt position of the backing materials with this overhanging edge raised, while at the same time, after this welding, the welding bead is covered with the same or surface layer of the thin plate. The protruding edges of both surface layers, which have been raised in advance, are placed on top of each other via an insert backing plate with a melting point higher than that of the insert, and the surface layer is welded along the protruding edges that occupy the outer side. Effectively preventing the plate from reaching the backing material,
This is a solution to the above problem.

Figure 1 shows an example of a tank lined according to the present invention, where a is a vertical sectional view and b is an internal view of the end plate. In this case, the inner diameter of the tank is 2600 mm.
mm, total length 12000mm, tank wall has inner plate thickness 2mm
The clad material is assembled by welding, which is made by explosively bonding a 40mm thick Ti plate to a 40mm thick steel plate, but the corrosion resistance of the Ti lining is insufficient under conditions where the operating temperature is relatively high, such as 260°C. According to this invention, Ta-Ti is
Lining with clad pieces was carried out as follows.

The corroded parts of the Ti lining were sanded to give a smooth finish, and test holes h and h' were drilled.

As a Ta-Ti clad piece, tantalum foil with a thickness of 0.6 mm was laminated on the entire surface of one side of a backing material (Ti) with a thickness of 5 mm by seam welding at a pitch of 25 mm.

This clad piece is made from the edge of the lining material in the form of a partial cylindrical segment spanning the lining height with a width that divides the circumference of the tank into 20 equal parts. As shown in Figure 2, the wide dimensions allow the ear edges to freely protrude from the lining material, and for the tank bottom mirror plate, there are also fan-shaped segments with a width that divides the tank circumference into 20 equal parts. and a circular plate with an outer diameter of 400 mm, prepared in the same manner as above, so that they could be carried into the tank through the manhole 2 of the tank 1 shown in Figure 1a.

In FIG. 2, 3 is a backing material, 4 is a surface layer, 5 is a seamless weld trace, 6 is a butt weld groove of the backing material, and 7 is an overhanging edge.

These clad pieces are sequentially carried into the tank 1 through the manhole 2 with an inner diameter of 500 mm, and as shown in FIG. as a backing material 3 of the adjacent piece along its inner surface.
First, butt welding is performed between them to join them together with the base metal 9, and then, at this time, they are raised as shown by the imaginary line to form the overhanging edge 7, which covers the weld bead 10 between them, with a thickness of 1 mm. The Ta plate is placed on the edge of the overhanging ear rim which is overlapped on the upper side of the figure, and the Ta plate is placed on the lower edge of the ear.
Welding 11 was performed. Although FIG. 3 shows the application to the inner periphery of the trunk wall, the same applies to the end plate, and the Ta weld 11 is shown by a solid line in FIG. 1b.

In Fig. 1a, 12 is the inner periphery of the welded joint between the body wall and head plate of the existing tank 1, and Ti
This is an annular joint plate that runs along the lining 9, and is made of a thin Ti plate.

After repair lining has been carried out over the necessary areas as described above, a color check is carried out over the entire surface, then a bubble test is carried out using test holes h and h', and finally a water pressure test is carried out to complete the construction.

In the illustrated example, a case has been described in which double lining is performed using the clad piece of the present invention for the Ti-lined part of the tank, but as shown in FIG. It is obvious that the lining according to the present invention can be applied in this case, and in this case, the lining material may be Ti, Cu, an alloy thereof, or a steel plate, and the surface layer may also be made of Ti, Cu, or a steel plate depending on the requirements for corrosion resistance. Ta, Nb, Zr, etc.
These clad pieces can be selectively joined together by spot welding in addition to the seam welding described above.

As described above, according to the present invention, thin plates of high-grade corrosion-resistant metal materials are laminated and combined by simply locally welding to the lining material, so lining material can be conveniently manufactured without requiring complicated processing to produce the cladding material. In particular, since welding is applied independently between the lining materials of the clad piece together with the base material and between the surface layers, there is no possibility of deterioration in the performance of the surface layer when the lining piece is attached to the base material. It is possible to reliably weld and fix the parts without causing damage.

[Brief explanation of drawings]

1A and 1B are a sectional view of a tank to which the present invention is applied and an inner view of a head plate, FIG. 2 is a perspective view of a clad piece, and FIGS. 3 and 4 are sectional views showing welding procedures. 3... Backing material, 4... Surface layer, 7... Overhanging edge, 10... Butt welding bead, P... Insert backing plate.

Claims (1)

[Scope of Claims] 1. A surface layer of a thin plate of highly corrosion-resistant metal material is superimposed on the entire surface of one side of the backing material, leaving a free protruding edge extending from the edge to at least the width of the butt weld bead to be applied to the backing material; The clad pieces, which have been joined together by watting and locally joined by electric resistance welding, are brought together on the surface of the base material to be lined, with the overhanging edges of the surface layer raised and the adjacent edges of the lining materials facing each other in a butt position. First, butt welding is performed on both backing materials together with the base material, and then an insert plate made of a highly corrosion-resistant metal material with a melting point equal to or higher than that of the surface layer is inserted to cover the bead of this butt weld. A lining construction method using clad pieces, which consists of overlapping and welding the overhanging edges of both surface layers. 2. The lining construction method according to 1, wherein the clad piece is locally joined by spot welding or seam welding. 3. The lining construction according to 1 or 2, wherein the cladding piece is made of a thin plate selected from titanium, tantalum, niobium, and zirconium, and a backing material of titanium, copper, or an alloy thereof, or iron or an iron alloy. Law. 4. The lining construction method according to 1, 2 or 3, wherein the lining material has an inclined edge forming a groove for welding.